Name the type of mirror used as shaving mirror.

What does the negative sign in the value of magnification produced by a mirror indicates about an image?

If you want to see an enlarged image of your face, will you use a concave mirror or a convex mirror?

In which of the following media: glass, water and diamond

(a) Light travels slowest.

(b) Light travels fastest.

Given below are refractive indices of a few material media.

Rock salt - 1.54

Ice - 1.31

Dense flint glass - 1.65

Crown glass - 1.52

Arrange the media in the ascending order of optical density.

An object of 1 cm in length is placed at a distance of 2f from a convex lens. What is the size of the image formed?

If the image formed by a lens is always diminished and erect, what is the nature of the lens?

A concave lens has a focal length of 50 cm. Calculate its power.

State two laws of reflection of light.

The magnification produced by a plane mirror is + 1. What does this mean?

Redraw the diagram given below in your answer book and complete the path of ray.

Draw a ray diagram to show why a stick half immersed in water appears to be bent at the surface.

Name the spherical mirror used as:

(a) Rear view mirror in vehicles

(b) Reflector in search-light.

What are laws of refraction of light?

An object is placed at a distance of 15 cm from a convex lens of focal length 20 cm. List four characteristics (nature, position, etc.) of the image formed by the lens.

Redraw the following diagram on your answer-sheet and show the path of the reflected ray. Also mark the angle of incidence (∠i) and the angle of reflection (∠r) on the diagram.

State the relation between object distance, image distance and focal length of a spherical mirror.

Draw a ray diagram to show the image formed when an object is placed between pole and focus of the concave mirror.

A child is standing in front of a magic mirror. She finds the image of her head bigger, the middle portion of her body of the same size and that of the leg smaller. Write the order of combinations for the magic mirror from the top.

The image of an object formed by a lens is real, inverted and of the same size as the object. If the image is at a distance of 40 cm from the lens, what is the nature and power of the lens? Draw ray diagram to justify your answer.

The image formed by spherical mirror is real, inverted and is of magnification-2. If the image is at a distance of 30 cm from the mirror, where is the object placed? Find the focal length of the mirror. List two characteristics of the image formed if the object is moved 10 cm towards the mirror.

The refraction index of a medium ‘X’ with respect to medium ‘Y’ is 2/3 and the refractive index of medium ‘Y’ with respect to medium ‘Z’ is 4/3. Find the refractive index of medium ‘Z’ with respect to medium ‘X’.

Which property of concave mirror is utilized for using them as shaving mirrors?

Light passes through a rectangular glass slab and through a triangular glass prism. Using proper ray diagram, explain in what way does the direction of the two emergent beams differs with respect to the incident beam of light.

A concave lens has a focal length of 50 cm Calculate its power.

A 10 mm long awl pin is placed vertically in front of a concave mirror. A 5 mm long image of the awl pin is formed at 30 cm in front of the mirror. Calculate the focal length of this mirror.

The magnification of an image formed by a lens is- 1. If the distance of the image from the optical centre of the lens is 35 cm, where is the object placed? What is the nature and focal length of the lens? If the object is displaced 20 cm towards the optical centre of the lens, where would the image be formed and what will be its nature? Draw a ray diagram to justify your answer.

An object is placed perpendicular to the principal axis of a convex lens of focal length 18 cm. The distance of the object from the lens is 27 cm. Find the position and nature of the image formed.

Draw the ray diagram to show the formation of image by a concave mirror of focal length 15 cm for the following positions of object. (Diagrams may not be drawn to the scale.)

Indicate is placed at 30 cm from mirror.

a. object is placed at 30 cm from mirror.

b. object is placed at 10 cm form the mirror.

Find the position of an object which when placed in front of a concave mirror of focal length 20 cm produces a virtual image twice the size of the object.

An object 2 cm in size is placed 20 cm in front of a concave mirror of focal length 10 cm. Find the distance from u the mirror at which a screen should be placed in order to obtain sharp image. What will be the size and nature of the image formed?

When an object is placed at a distance of 60 cm from a convex mirror the magnification produced is 1/2. Where should the object be placed to get a magnification of 1/3.

A concave lens has focal length of 20cm. At what distance from the lens a 5 cm tall object be placed so that it forms an image at a distance of 15 cm from the lens? Also calculate the size of the image formed.

At what distance should an object be placed from a convex lens of focal length 18 cm to obtain an image at 36 cm from it? What will be the magnification produced in this case?

You have two lenses A and B of focal lengths + 10 cm and – 10 cm respectively. State the nature and power of each lens. Which of the two lenses will form a virtual and magnified image of an object placed 8 cm from the lens? Draw a ray diagram to justify your answer.

Draw the ray diagram in each case to show the position and nature of the image formed when the object is placed:

(i) In front of a convex lens at F,

(ii) At 3F of a convex lens,

(iii) Between the lens and infinity of a concave lens.